Inflammation is a local or systemic protective response to the injury or infection of cells or tissues. However, inflammation may lead to a large number of diseases due to an imbalance of inflammatory cytokines and by the interaction between effector cells. Main inflammatory diseases include: rhinitis and sinusitis such as infectious rhinitis, allergic rhinitis, chronic rhinitis, acute sinusitis and chronic sinusitis; pneumonia such as bacterial pneumonia, bronchial pneumonia, lobar pneumonia, Legionella pneumonia and viral pneumonia; otitis media such as acute purulent otitis media and chronic purulent otitis media; acute or chronic gastritis; enteritis such as infectious enterocolitis, Crohn's disease, idiopathic ulcerative colitis and pseudomembranous colitis; arthritis such as septic arthritis, tuberculous arthritis, degenerative arthritis and rheumatoid arthritis; and diabetic ocular disease.
MCP-1, also called chemokine (C-C motif) ligand 2 (CCL2), is a small cytokine belonging to the CC chemokine family. MCP-1 recruits monocytes and subset of lymphocytes (Mol Med Today (1996) 2: 198-204; J Leukoc Biol (1999) 65: 482-491). In previous studies, a high level of MCP-1 was detected in the branchoalveolar lavage fluids (BALF) and serum of patients with pulmonary sarcoidosis (Internal Med (1997) 36: 856-860; Clin Exp Immunol (1998) 111:604-610; Eur Res J (2002) 20:1206-1212; Res Med (2004) 98: 945-951), and it was suggested that MCP-1 served as an important mediator that dictated the granuloma progression. MCP-1 is also known to play an important role in the pathogenesis of many diseases such as asthma, interstitial lung diseases, and tumors. However, most studies are performed in in vitro experiments.
It is therefore desired to develop an animal model to study MCP-1 expression in vivo and further to screen for an agent that regulates MCP-1 expression or an agent that treats an inflammation disorder especially that where MCP-1 plays a key role.